Pump device



Oct. 6, 1964 c. A. SWARTZ 3,151,562

PUMP DEVICE Filed April 25, 1962 2 Sheets-Sheet 2 INVENTOR.

CHARLES A SWARTZ ATTORNEYS Filed Apr. 25, 1962, Ser. No. 190,178 7Claims. (Cl. 103-44) This invention relates to positive displacementfluid pumps, and more particularly to an improvement in reciprocatingpumps wherein the reciprocating member is separated from the liquidbeing pumped.

Pumps in which the reciprocating member of the pump acts through anintermediate separating member such as a diaphragrn or a liquid surgecolumn, or in combination a liquid surge column and a diaphragm, havebeen known generally in connection with the pumping of corrosive, toxic,or flammable liquids. While pumps using a diaphragm or bellows toseparate the surge column and stufling box from the liquid being pumpedare well known, they are not adapted for the delivery of large requiredcapacities, because of high cost and excessive maintenance requirements.Generally, the intermediate separating diaphragm or bellows is notadapted to withstand substantial pressure diflerentials across itswalls.

It is an object of the invention to provide an improved positivedisplacement reciprocating pump in which the liquid being pumped iseffectively separated from the intermediate liquid surge column andeffectively sealed from the plunger stufiing box.

Another object of the invention is to provide an improved positivedisplacement reciprocating pump in which the liquid pumped is beingmaintained remote from the actuating plunger when the circumstances sorequire, e.g. in the pumping of radioactive liquids.

It is another object of the invention to provide a bellows-type pump formoving liquid, including means for balancing the pressure at all timesacross the bellows.

According to one embodiment of the invention, the bellows is separatedfrom the plunger by a liquid actuating column i.e. a surge column forthe transmitting of the reciprocation of the plunger to the bellows,causing the latter to reciprocate along with the plunger, the bellowsalso separating the liquid being pumped in the surge block from theliquid in the surge column.

Disposed hydraulically between the liquid to be pumped and the liquidsurge column is the pressure equalizing arrangement which in thepreferred embodiment includes a pressure balancing valve, a check valveand an accumulator reservoir, one side of the pressure balancing valvebeing in connection with the side of the liquid to be pumped while theother side of the valve is in connection with the surge column,consisting of an inert liquid, the check valve and the accumulatorreservoir serving to replenish the inert liquid in the surge column.

In another embodiment a direct mechanical connection is provided betweenthe plunger and a bellows type mechanical sealing member, one end ofwhich is attached to the plunger, the other to the stufling box housing.

Similarly to the first mentioned embodimenhthe second embodiment alsoincludes a pressure balancing mechanism connected to the device in amanner similar as in the previous embodiment for the inert liquiddisposed at the side of the bellows opposite the side contacting theliquid to be pumped. Preferably, the plunger in this embodiment isformed with a shoulder so dimensioned as to maintain a pressure in theinert liquid surge column substantially equal to the pressure in theliquid being pumped and adapted to supplement the pressure equalizingfunction of the pressure balancing valve by providing additionalpressure or suction, depending on the stroke of the plunger, to theplunger side of the pressure balancing valve.

United States Patent 3,151,562 Patented Oct. 6, 1964 ice Additionalfeatures and advantages of the invention will become apparent from thefollowing detailed description and drawing, wherein:

FIG. 1 is a cross-sectional view of one embodiment of a pump accordingto the invention;

FIG. 2 is an enlarged scale showing of the bellows in FIG. l;

3 is an end elevational view taken along line 33 of FIG. 2;

FIG. 4 is a cross-sectional view of a somewhat difierent embodiment ofthe pump shown in FIG. 1;

FIG. 5 is an end elevational view taken along line 55 of FIG. 4; and

FIG. 6 is a cross-sectional view of another embodiment of the pumpaccording to the invention.

Referring to FIGS. l-3, a pump is shown having an inlet 1 and an outlet2 where suitable unidirectional inlet valve means 4 and outlet valvemeans 6 are disposed in a surge block 8. The liquid to be pumped passesthrough the surge block 8. Attached to the surge block 8 is housing 10with a stufling box by means of eg a lens joint 12. In place of the lensjoint 12 alternatively, other commercial type joints may be used, suchas raised face, tongue and groove ring, joint, male and female and soon.

Bellows 14 made of flexible metal or other suitable material is firmlyheld in the joint 12 by a flange 16 forming part of the bellows 14. Theend of the bellows 14 having the flange 16 thereon, is open, as shown inFIG. 3, except for spoke 18 which support a central guide part in thebellows, to be described later. The end of the bellows facing the surgeblock is closed ofi by means of a closure member 20. Disposed within thebellows and outside of the bellows at its end past the flange 16 is aninert liquid, constituting the surge column 22. The surge column 22establishes the actuating coupling between a plunger 24 disposed at theend of the surge column 22 opposite the bellows 14. The plunger 24 isadapted to reciprocate within the stufling box and housing 10 in thedirection of the double headed arrow A, driven by a suitable outsidedriving mechanism (not shown). The plunger 24 may be provided withsealing rings 26 and/or a packing 2S, establishing the seal between thestufiing box housing 19 and the plunger 24. The packing 28 is maintainedas a compression seal by means of a packing gland 3t) and gland bolts32, pressing the packing gland and the packing 28 into the sealingrelationship.

A rod 34 (FIGURE 2) is attached at its one end to the closure member 20.A guiding sleeve 36 is threadedly fixed within the flange 16. The otherend of the rod 34 projects through a central bore in the guiding sleeve36 and a stop member 38 is attached to the free end of the rod 34. Asthe bellows expand or contract, the rod 34 can freely glide within theguiding sleeve 36. The length of the stroke of the bellows is adjustedby rotating the guiding sleeve 36 in the flange 16. For increasedflexibility of adjustment in the stroke length if desired, the stopmember 38 can be formed as an adjusting nut, adapted to engage acomplementarily threaded portion of the rod 34. End 40 of the guidesleeve 3:: disposed within the bellows is adapted to abut against theinner surface of the closure member 20 to restrict, if necessary, thecontracting of the bellows to the desired lengthof stroke.

One side of a pressure balancing valve 42 is connected to an outlet 44in the surge block 8 for the sensing of the pressure in the liquid to bepumped therein. Additional means 46 can be provided for relief valve torelieve excess pressure in the liquid in the surge block 8 inthe case adangerous pressure buildup may occur, e.g. if for some reason thedischarge valve 6 from the surge block should be inadvertently closedwhile the pump isv running. The other end of the pressure balancingvalve V actuating column.

the bellows. 1

42 is connected to an outlet 48 in the stutlingbox housing incommunication with the surge column liquid. In the preferred embodiment,the principal element of the pressure balancing valve 42 is a pressurebalancing bellows 50. When the pressure is suitably balanced by thevalve 42, minimum pressure differential exists between the inside andoutside of the bellows 14. The connection 43 also establishescommunication of the actuating liquid through a check valve 52 with anactuating liquid reservoir '54 to provide actuating liquid replenishmentto the surge column 22 to maintain the proper volume of liquid therein.A venting valve 56 is provided on the actuating liquid side of thepressure balancing valve 42 so that if the pressure in the actuatingcolumn 22 for some reason would become too high, the excess liquid canbe drained off through the venting valve 56. If desired, a connectioncan be established between the outlet of the venting valve 56 and theactuating liquid reservoir 54 to preserve the drained oif liquid forreuse. The actuating liquid reservoir also aids in replenishing liquidlost from the actuating column 22 by possible leakage through thestufiing box pachng 28. The actuating liquid reservoir 54 is pressurizedpreferably at approximately the suction pressure in the surge block 8.If the pressure of the actuating column drops below the pressure in thereservoir due to loss of inert liquid, the check valve 52 allows flowfrom the reservoir to the During this inert liquid replenishingcondition the venting valve 56 would be closed due to l the pressure onthe pressure balancing bellows 50 on the surge block side being higher.

The additional venting means 46 or relief valve is designed to relieveunusually high pressure within the surge blockr A spring 57 is providedwith the pressure balancing bellows 50, forcing same to keep the ventingvalve 56 closed. The pressure of this spring, combined with theeffective area of the pressure balancing bellows 50 gives the minimumpressure dififerential which is desired to be maintained across thebellows 14. In the case. of general pumping applications this minimumpressure differential value would be preferably as low as possible.preferred mode of operation and under preferred balanced conditions, thebellows 14 will always stroke together with the plunger 24. r

In one embodiment, e.g. the one shown in FIG. 1, if desired, a linermade from a suitable material can be provided within that portion of thesurge block 8 in which the bellows 14 reciprocates, to hold the flange16 of the bellows firmly against the housing 10. A cover 59 is providedfor the surge block 8, the cover permitting :removal of the liner fromthe surge block and also providing' for the removal of the bellowsthrough the block without unnecessary dismantling of the pump. The linerwould, of course, be provided with suitable openings for the flow ofliquid'to be pumped through valves 4 and 6 in the'surge block. 7

' In FIGS. 4 and 5 an embodiment similar to the one discussed previouslyis shown; incorporating some modifications thereover. In FIG. 4 aspoolpiece 60 is "into the surge block housing 10 from the joint 64 asin FIG. 1, or disposed within the spoolpiece 60 andmain tained thereinat the joint 62, as in FIG. 4. The cover 59 providing for the removalofthe bellows 14, can be omitted if a spoolpiece is In FIG. 4; optionalcooling or heating rneans 68 is shown in the embodiment of a coilsurrounding the spoolpiec'e 6%}. However, if desired and thetemperatureof ;:liquid, to be p umped would require, cooling or heating.

In the used for the disposition'of couldbe applied to any portion of thepump, stuffing box, surge column, or surge block.

Spoolpiece allows for rapid disassembly in case that this may benecessary, providing for easy removal or replacement of the bellows. Theinside diameter of the stuifing box housing 14), the spoolpiece 60 andthe bore in the surge block 8 should preferably be as closely identicalas possible so as to avoid significant changes of velocity in theactuating'liqnid during each stroke to avoid pressure impulses orharmonics in addition to the usual pulsations of a reciprocating pump.The equalizing of the dimensions also contributes to the bellows and theplunger stroking together'in the desired relationship. The pressure ofthe liquid in the surge block can be taken off for purposes of pressurebalancing either at the surge block housing 8, as shown in FIG. 1, or atthe spoolpiece 60 as shown in FIG. 4 at 70.

As also shown in FIG. 5, sliding shoes 72 can be provided for the endplate of the bellows 66 to keep' it within the desired centraldisposition within that part of the housing within which it ispositioned to reciprocate. If sliding shoes 72 are used, preferably aliner, similar to the one shown at 53 in FIG. 1, can be employed ifdesirable upon which the shoes 72 ride back and forth.

In FIG. 6 another embodiment of the pump according to the invention isshown, wherein a composite plunger 74 is provided extending from astufiing box housing 76 to a surge block 73. The liquid to be pumpedwithin the surge block 78 is completely isolated from the stulfing boxpacking 80 by a bellows 82. In FIG.'6 the bellows is attached at its endfacing the surge block 78 to the plunger 74 and to the stufling boxhousingon the side facing the packing 78. If desired, the bellows 82canbe attached to the plunger 74 on the side facing the packing 80,depending on convenience. The space provided in the interior of thebellows of the pump shown in FIG. 6 is filled with an inert liquid whichis provided to maintain pressure on the inner wall of the bellows, tobalance the pressure of the liquid to be pumped on the outer side of thebellows 82. The inert liquid here, as in the other embodiments, may bewater or some other suitablehydraulic fluid.

The principle of the embodiment shown in FIG. 6 can also be applied topiston pumps instead of plunger pumps, simply by adapting the same .typeof connection to a piston rod and the stufiing box housing instead of aplunger and the stufilng box housing.

In order to assure negligible differential pressure across the bellowswalls, a balancing system similar to the one shown in FIG. 1 isindicated. The pressure of the liquid to be pumped is taken off at anoutlet 84, while the connection to the inert liquid is made at an outlet86.

The plunger 74 is shown to be formed with a shoulder 88, which maintainsthe pressure within the bellows in shown interposed between the surgeblock 8 and the i accordance with'the pressure in the liquid beingpumped and in accordance with the stroking of the pump, for negligibledifferential pressure inside and outside the bel- 1 lows wall.

The pump can be built as a single unit or in duplex,

triplex, or multiplex form including any necessary num{ ber of cylindersto obtain most economically the delivery and capacity desired. The surgeblock member can be formed of individual castingsor forgings, one foreach plunger, or alternatively can'be a forging or casting of two ormore pumps enblock. Suction and discharge manifolds can be formedintegral with the forging or casting or can be provided as separatepieces tobe bolted to the individual blocks; 1

V Whilespeeific embodiments of the invention are shown, other pressurebaiancing'and sealing arrangements: could also be provided within thescope of the invention, therefore, the scope thereof is to beinterpreted from the appended claims.

1 claim:

I. A high pressure and large volume liquid displacement pump comprisinga housing having an elongated cylindrical chamber therein ofsubstantially the same diameter throughout its length, bellows meanssecured to said housing for divid ng said chamber into a first portionfor containing an inert liquid on one side of said bellows means andinto a second portion for containing the liquid to be pumped, a plungerreciprocable in said first portion for alternately raising and loweringthe pressure of the inert liquid therein and efiecting a correspondingalternate extension of the bellows means into and out of said secondportion, fluid inlet and outlet means in communication with said secondportion for passage of the liquid to be pumped therethrough; saidbellows means including a substantially cylindrical bellows, a rigid endplate for said bellows having substantially the same effective area asthe end area of said plunger, a guide rod secured at one end thereoi toa central portion of said end plate in the interior of said bellows andextending internally along the longitudinal axis of said bellows, meanscooperating with said guide rod for limiting the maximum extension ofsaid bellows, and pressure limiting means responsive to the differentialpressure between the liquids in said first and second portions of saidchamber, said pressure limiting means including a casing, an auxiliarybellows secured at one end thereof within said casing and dividing itinto a first part ad a second part, the first part being in fluidcommunication with said chamber first portion, the second part being influid communication with said chamber second portion, a rigid closureplate attached to the other end of said auxiliary bellows, said firstpart including an aperture in the wall of said casing opposite saidclosure plate for venting motivating liquid from the first part, saidclosure plate including plug means in line with the aperture forcontrolling the venting of said first part through said aperture, andspring means for normally biasing said closure plate and the plug meansthereon to seal the aperture, whereby upon an increase in the pressureor" the motivating liquid in the first portion beyond a predetermineddifferential with the pressure in the second portion the plug meansoperates to vent excess motivating liquid through the aperture until apredetermined maximum value of dififerential pressure between said firstand second portions is restored.

2. A liquid displacement pump according to claim 1, wherein said meanscooperating with said guide rod for limiting the maximum extension ofsaid bellows comprises means for attaching the free end of said guiderod to said plunger.

3. A high pressure and large volume liquid displacement pump comprisinga housing having an elongated cylindrical chamber therein ofsubstantially the same diameter throughout its length, bellows meanssecured to said housing for dividing said chamber into a first portionfor containing an inert motivating liquid on one side of said bellowsmeans and into a second portion for containing the liquid to be pumped,a plunger reciprocable in said first portion for alternately raising andlowering the pressure of the motivating liquid therein and efiecting acorresponding alternate extension of the bellows means into and out ofsaid second portion, fluid inlet and outlet means in communication withsaid second portion for passage of the liquid to be pumped therethrough;said bellows means including a substantially cylindrical bellows made ofa metallic material, a rigid end plate for said bellows havingsubstantially the same effective area as the end area of said plunger, aguide rod secured at one end thereof to a central portion of said endplate in the interior of said bellows and extending internally along thelongitudinal axis of said bellows, support means extending transverselyof said chamber for engaging and guiding the free end of said guide rodas said end plate reciprocates with displacement of said plunger,adjustable stop means connected to the free end or" said guide rod andcooperating with said support means for limiting the maximum extensionof said bellows; and pressure limiting means responsive to thedifierential pressure between the liquids in said first and secondportions of said chamber, said pressure limiting means including acasing, an auxiliary bellows secured at one end thereof within saidcasing and dividing it into a first part and a second part, the firstpart being in r'iuid communication with said chamber first portion, thesecond part being in fiuid communication with said chamber secondportion, a rigid closure plate attached to the other end of saidauxiliary bellows, said first part including an aperture in the wall ofsaid casing opposite said closure plate for venting motivating liquidfrom the irst part, said closure plate including plug means in line withthe aperture for controlling the venting of said first part through saidaperture, and spring means for normally biasing said closure plate andthe plug means thereon to seal the aperture, whereby upon an increase inthe pressure of the motivating liquid in the first portion beyond apredetermined difierential with the pressure in the second portion theplug means operates to vent excess motivating liquid through theaperture until a predetermined maximum value of diilerential pressurebetween said first and second portions is restored.

4. A liquid displacement pump according to claim 3, wherein said housingincludes a first section in which substantially all of said chamberfirst portion is formed, and a second section in which substantially allof said chamber second portion is formed, means for securing said firstand second sections to each other, and wherein said support meansincludes a circular flange attached at the periphery thereof to saidhousing between said first and second sections, said flange being formedwith an opening therein for establishing fluid communication betweensaid chamber first portion and the interior of said bellows, said flangefurther including and mounting adjustable means for limiting the minimumlongitudinal dimension of said bellows.

5. A liquid displacement pump according to claim 4, wherein the end ofsaid bellows opposite to the end carrying said end plate is attached tosaid flange, and said adjustable means comprises an externally threadedsleeve threaded into said flange substantially coaxially with the guiderod, said guide rod being adapted to slide within said sleeve during thereciprocations of said bellows, whereby said bellows with said flangeforms a unitary subassembly for ease of replaceability of said bellowsmeans in said housing.

6. A liquid displacement pump according to claim 4, further including anintermediate housing section attached to said housing between said firstand second sections thereof for ease or accessibility to said bellowsmeans.

7. A liquid displacement pump according to claim 3, wherein said housingfurther includes a stuffing box surrounding said plunger for sealingsaid inert liquid within the first portion of the chamber, and means forcontrolling the temperature of the vicinity of said bellows means.

References Cited in the tile of this patent UNITED STATES PATENTS1,408,208 Jones Feb. 28, 1922 1,627,257 Stevens May 3, 1927 2,753,805Boiviuet July 10, 1956 FOREIGN PATENTS 849,414 France Nov. 23, 1939470,734 Italy Apr. 22, 1952

1. A HIGH PRESSURE AND LARGE VOLUME LIQUID DISPLACEMENT PUMP COMPRISINGA HOUSING HAVING AN ELONGATED CYLINDRICAL CHAMBER THEREIN OFSUBSTANTIALLY THE SAME DIAMETER THROUGHOUT ITS LENGTH, BELLOWS MEANSSECURED TO SAID HOUSING FOR DIVIDING SAID CHAMBER INTO A FIRST PORTIONFOR CONTAINING AN INERT LIQUID ON ONE SIDE OF SAID BELLOWS MEANS ANDINTO A SECOND PORTION FOR CONTAINING THE LIQUID TO BE PUMPED, A PLUNGERRECIPROCABLE IN SAID FIRST PORTION FOR ALTERNATELY RAISING AND LOWERINGTHE PRESSURE OF THE INERT LIQUID THEREIN AND EFFECTING A CORRESPONDINGALTERNATE EXTENSION OF THE BELLOWS MEANS INTO AND OUT OF SAID SECONDPORTION, FLUID INLET AND OUTLET MEANS IN COMMUNICATION WITH SAID SECONDPORTION FOR PASSAGE OF THE LIQUID TO BE PUMPED THERETHROUGH; SAIDBELLOWS MEANS INCLUDING A SUBSTANTIALLY CYLINDRICAL BELLOWS, A RIGID ENDPLATE FOR SAID BELLOWS HAVING SUBSTANTIALLY THE SAME EFFECTIVE AREA ASTHE END AREA OF SAID PLUNGER, A GUIDE ROD SECURED AT ONE END THEREOF TOA CENTRAL PORTION OF SAID END PLATE IN THE INTERIOR OF SAID BELLOWS ANDEXTENDING INTERNALLY ALONG THE LONGITUDINAL AXIS OF SAID BELLOWS, MEANSCOOPERATING WITH SAID GUIDE ROD FOR LIMITING THE MAXIMUM EXTENSION OFSAID BELLOWS, AND PRESSURE LIMITING MEANS RESPONSIVE TO THE DIFFERENTIALPRESSURE BETWEEN THE LIQUIDS IN SAID FIRST AND SECOND PORTIONS OF SAIDCHAMBER, SAID PRESSURE LIMITING MEANS INCLUDING A CASING, AN AUXILIARYBELLOWS SECURED AT ONE END THEREOF WITHIN SAID CASING AND DIVIDING ITINTO A FIRST PART AND SECOND PART, THE FIRST PART BEING IN FLUIDCOMMUNICATION WITH SAID CHAMBER FIRST PORTION, THE SECOND PART BEING INFLUID COMMUNICATION WITH SAID CHAMBER SAID PORTION, A RIGID CLOSUREPLATE ATTACHED TO THE OTHER END OF SAID AUXILIARY BELLOWS, SAID FIRSTPART INCLUDING AN APERTURE IN THE WALL OF SAID CASING OPPOSITE SAIDCLOSURE PLATE FOR VENTING MOTIVATING LIQUID FROM THE FIRST PART, SAIDCLOSURE PLATE INCLUDING PLUG MEANS IN LINE WITH THE APERTURE FORCONTROLLING THE VENTING OF SAID FIRST PART THROUGH SAID APERTURE, ANDSPRING MEANS FOR NORMALLY BIASING SAID CLOSURE PLATE AND THE PLUG MEANSTHEREON TO SEAL THE APERTURE, WHEREBY UPON AN INCREASE IN THE PRESSUREOF THE MOTIVATING LIQUID IN THE FIRST PORTION BEYOND A PREDETERMINEDDIFFERENTIAL WITH THE PRESSURE IN THE SECOND PORTION THE PLUG MEANSOPERATES TO VENT EXCESS MOTIVATING LIQUID THROUGH THE APERTURE UNTIL APREDETERMINED MAXIMUM VALUE OF DIFFERENTIAL PRESSURE BETWEEN SAID FIRSTAND SECOND PORTIONS IS RESTORED.